You forgot the unset() in there bro. function buildTree(array &$elements, $parentId = 0) { $branch = array(); foreach ($elements as $element) { if ($element[‘parent_id’] == $parentId) { $children = buildTree($elements, $element[‘id’]); if ($children) { $element[‘children’] = $children; } $branch[$element[‘id’]] = $element; unset($elements[$element[‘id’]]); } } return $branch; }
oke this is how i solved it: $arr = array( array(‘id’=>100, ‘parentid’=>0, ‘name’=>’a’), array(‘id’=>101, ‘parentid’=>100, ‘name’=>’a’), array(‘id’=>102, ‘parentid’=>101, ‘name’=>’a’), array(‘id’=>103, ‘parentid’=>101, ‘name’=>’a’), ); $new = array(); foreach ($arr as $a){ $new[$a[‘parentid’]][] = $a; } $tree = createTree($new, array($arr[0])); print_r($tree); function createTree(&$list, $parent){ $tree = array(); foreach ($parent as $k=>$l){ if(isset($list[$l[‘id’]])){ $l[‘children’] = createTree($list, $list[$l[‘id’]]); } … Read more
Assuming this is some kind of homework and you want to do it yourself.. I did this once, you need a stack So what you do for the example is: parse what to do? Stack looks like ( push it onto the stack ( 5 push 5 (, 5 + push + (, 5, + … Read more
You’re looking for the for…in loop: for (var key in foo) { if (key == “child”) // do something… } Be aware that for…in loops will iterate over any enumerable properties, including those that are added to the prototype of an object. To avoid acting on these properties, you can use the hasOwnProperty method to … Read more
This requires a very basic recursive function to parse the child/parent pairs to a tree structure and another recursive function to print it out. Only one function would suffice but here’s two for clarity (a combined function can be found at the end of this answer). First initialize the array of child/parent pairs: $tree = … Read more
You can flatten a tree like this: IEnumerable<MyNode> Flatten(IEnumerable<MyNode> e) => e.SelectMany(c => Flatten(c.Elements)).Concat(new[] { e }); You can then filter by group using Where(…). To earn some “points for style”, convert Flatten to an extension function in a static class. public static IEnumerable<MyNode> Flatten(this IEnumerable<MyNode> e) => e.SelectMany(c => c.Elements.Flatten()).Concat(e); To earn more points … Read more
Here: public class Tree<T> { private Node<T> root; public Tree(T rootData) { root = new Node<T>(); root.data = rootData; root.children = new ArrayList<Node<T>>(); } public static class Node<T> { private T data; private Node<T> parent; private List<Node<T>> children; } } That is a basic tree structure that can be used for String or any other … Read more
Build tree array from flat array in javascript
Now that MySQL 8.0 supports recursive queries, we can say that all popular SQL databases support recursive queries in standard syntax. WITH RECURSIVE MyTree AS ( SELECT * FROM MyTable WHERE ParentId IS NULL UNION ALL SELECT m.* FROM MyTABLE AS m JOIN MyTree AS t ON m.ParentId = t.Id ) SELECT * FROM MyTree; … Read more
My favorite answer is as what the first sentence in this thread suggested. Use an Adjacency List to maintain the hierarchy and use Nested Sets to query the hierarchy. The problem up until now has been that the coversion method from an Adjacecy List to Nested Sets has been frightfully slow because most people use … Read more